1. Field of the Invention
The present invention relates to a magnetic recording medium such as magnetic tape, and in particular to a magnetic recording medium preferable in electromagnetic conversion characteristics.
2. Description of Related Art
Magnetic recording medium has widely been used as an external storage media for audio components, video recorders, computers and so forth. With recent advances in shorter recording wavelength, higher density and larger capacity of recording/reproducing devices, there has been large growing demands for improvement in electromagnetic conversion characteristics of coating-type magnetic recording medium, so that efforts have been made on obtaining thinner magnetic layer, higher filling factor and finer grain size of magnetic powder, and smoother surface.
A magnetic recording medium having an improved electromagnetic conversion characteristics is typically proposed in the Patent Document 1. (Patent Document 1: Japanese Patent Application Publication No. 2000-231713)
The coating-type magnetic recording medium, however, suffers from a problem that, for the purpose of obtaining a practically-satisfactory durability, the magnetic layer of which must be added with materials which are not essential for recording, such as lubricant and abrasive, beside binder, and this results in further lowering in the filling factor and in the output.
One possible method of increasing the recording density is to reduce grain size of ferromagnetic powder. Excessive size reduction, however, results in difficulty in dispersion of the magnetic coating, and in lowered output. The poor dispersion also worsens the surface property, increases noise, and degrades the electromagnetic conversion characteristics, all of which remain to be addressed.
It is therefore a subject of the present invention to provide a coating-type magnetic recording medium having preferable electromagnetic conversion characteristics suitable for high-density recording.